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Teixeira A.L.,Maternity Hospital Therezinha de Jesus | Teixeira A.L.,State University of Rio de Janeiro | Ramos P.S.,Maternity Hospital Therezinha de Jesus | Vianna L.C.,University of Brasilia | Ricardo D.R.,Maternity Hospital Therezinha de Jesus
Psychophysiology | Year: 2015

Previous studies have shown that resting heart rate variability (HRV) is modified by different phases of the menstrual cycle in nonusers of oral contraceptive pills (OCP); however, the effect of OCP on autonomic control of the heart remains unclear. The purpose of this study was to investigate HRV during the low hormone (LH-not taking OCP) and during the high hormone (HH-active OCP use) phases of the menstrual cycle in young women. Seventeen healthy women (19-31 years) taking OCP for at least 6 consecutive months were enrolled in this study. Plasma estradiol and progesterone were verified at each visit. HRV was assessed by using one-lead electrocardiography in time and frequency domains, in which participants rested in the supine position for a 20-min period with a breathing rate of 15 cycles/min. In addition, resting heart rate, and systolic and diastolic blood pressure were obtained. Both plasma estradiol (LH: 19.8±4.2 pg/mL vs. HH: 12.4±1.5 pg/mL; p>.05) and progesterone (LH: 0.247±0.58 ng/mL vs. HH: 0.371±0.08 ng/mL; p>.05) (mean±SE) levels were similar in both phases. No significant difference was obtained for any component of HRV, heart rate, or blood pressure between the LH and HH phases (p>.05). These results provide preliminary evidence that use of OCP does not affect HRV during the menstrual cycle in healthy women. © 2015 Society for Psychophysiological Research.


Teixeira A.L.,Maternity Hospital Therezinha de Jesus | Ramos P.S.,Maternity Hospital Therezinha de Jesus | Marins J.B.,Federal University of Vicosa | Ricardo D.R.,Maternity Hospital Therezinha de Jesus
International Journal of Sports Medicine | Year: 2014

The aim of this study was to assess the hypothesis that water intake will accelerate cardiac vagal reactivation after a single session of upper-body resistance exercise. 13 healthy men (26.5±5.9 years) with previous experience in resistance training were enrolled. In visits 1 and 2, participants performed the one-repetition maximum (1RM) test and retest with the bench press exercise. The sessions 3 and 4 were performed randomly, while participants consumed 500 ml (experimental visit) or 50 ml (control visit) of water immediately after 3 sets of maximum repetitions at 80% of 1RM. Cardiac vagal activity was represented by cardiac vagal index (CVI) measured before, immediately after and 30 min post-exercise. Additionally, heart rate and blood pressure were measured. The results show that CVI was higher 30 min post-exercise when 500 ml of water was ingested compared to 50 ml (1.39±0.07 vs. 1.23±0.07; p=0.02) (mean±SEM). Heart rate and blood pressure values were similar in both trials. We conclude that water intake accelerates post-resistance exercise cardiac vagal reactivation. These findings suggest that hydration after resistance exercise might be beneficial for cardiovascular safety in healthy subjects.


Teixeira A.L.,Maternity Hospital Therezinha de Jesus | Teixeira A.L.,State University of Rio de Janeiro | Ramos P.S.,Maternity Hospital Therezinha de Jesus | Ramos P.S.,State University of Rio de Janeiro | And 3 more authors.
PLoS ONE | Year: 2015

The purpose of this study was to investigate the effects of the ovarian hormones and the use of oral contraceptive pills (OCP) on cardiac vagal withdrawal at the onset of dynamic exercise. Thirty physically active women aged 19-32 years were divided into two groups: OCP users (n = 17) and non-OCP users (n = 13). Participants were studied randomly at three different phases of the menstrual cycle: early follicular (day 3.6 ± 1.2; range 1-5), ovulatory (day 14.3 ± 0.8; range 13-16) and midluteal (day 21.3 ± 0.8; range 20-24), according to endogenous (in non-OCP users) or exogenous (in OCP users) estradiol and progesterone variations. The cardiac vagal withdrawal was represented by the cardiac vagal index (CVI), which was obtained by the 4-s exercise test. Additionally, resting heart rate, systolic (SBP) and diastolic blood pressure (DBP) were obtained. The CVI was not significantly different between the three phases of the menstrual cycle in either the non-OCP users (early follicular: 1.58 ± 0.1; ovulatory: 1.56 ± 0.1; midluteal: 1.58 ± 0.1, P > 0.05) or OCP users (early follicular: 1.47 ± 0.1; ovulatory: 1.49 ± 0.1; midluteal: 1.47 ± 0.1, P > 0.05) (mean ±SEM). Resting cardiovascular responses were not affected by hormonal phase or OCP use, except that the SBP was higher in the OCP users than non-OCP users in all phases of the cycle (P < 0.05). In summary, our results demonstrate that cardiac vagal withdrawal at the onset of dynamic exercise was not impacted by the menstrual cycle or OCP use in physically active women. © 2015 Teixeira et al.

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